CN114787763B - Electronic shelf label system with energy supply for consumers for long-term operation of shelf labels - Google Patents

Abstract

A method for operating an electronic shelf label system (1), wherein the system comprises a shelf label (201-211) fastened to a shelf rail (3), wherein the shelf label is designed to be supplied with energy in a contactless manner, and the shelf rail comprises a supply device (21) for supplying energy to the shelf label fastened to the shelf rail in a contactless manner, and the shelf rail comprises at least one wire loop (L), wherein the wire loop is a component of the supply device of the shelf rail, and the wire loop is used to output a signal that can be generated by the supply device for the purpose of supplying energy to the shelf label positioned on the shelf rail corresponding to the wire loop, wherein according to the method, the signal is generated by means of the supply device and output via the wire loop, and the corresponding shelf label positioned corresponding to the wire loop stores the electrical energy transmitted from the supply device to the shelf label by means of the signal in a rechargeable long-term energy storage device, and uses the electrical energy for operating the shelf label outside the time interval when the signal is present.

Description

Electronic shelf label system with energy supply for consumers for long-term operation of shelf labels

Technical Field

The invention relates to an electronic shelf label system with energy supply via shelf rails for consumers operating shelf labels for a long time.

Background

An electronic shelf label system (hereinafter referred to as ESL system for short, wherein ESL stands for "electronic shelf label (Electronic Shelf Label)") for displaying information by means of an electronic shelf label display with energy supply via a shelf rail is known, for example, from international patent application WO 2017/153481 A1. In the case of the known ESL system, the shelf rail on which the ESL is arranged is equipped with electrical conductor tracks, which are connected to a power supply for supplying the ESL with electricity. The ESL has a spring contact at its back side with which the conductor track is brought into contact in order to electrically connect the ESL to a power supply.

However, the known energy supply is relatively expensive, since a large number of, in particular separate, mechanical components should be provided in each ESL and in each shelf rail. These mechanical parts are subject to natural wear. Furthermore, the mechanical components may be contaminated or even damaged when not handled properly. This may lead to disturbances in operation. Considerable additional effort in terms of manufacturing and maintenance also occurs with respect to the mechanical components, which is necessary in order to avoid the problems mentioned. In the known systems, there is furthermore a limitation that the ESL cannot be positioned or moved along the shelf rail freely selectable.

The present invention addresses the task of providing an improved ESL system in which the above-mentioned problems are overcome.

Disclosure of Invention

This object is achieved by a method for operating an electronic shelf label system, wherein the system has shelf labels fastened to a shelf rail, wherein the shelf labels are configured to be supplied with energy in a contactless manner, and the shelf rail has a supply device for supplying energy to the shelf labels fastened to the shelf rail in a contactless manner, and the shelf rail has at least one wire loop, wherein the wire loop is part of a supply device of the shelf rail, and the wire loop is used for outputting a signal which can be generated by the supply device for the purpose of supplying energy to the shelf labels positioned at the shelf rail corresponding to the wire loop, wherein the signal is generated by means of the supply device according to the method, and the signal is output via the wire loop, and the respective shelf label positioned corresponding to the wire loop stores the electrical energy which is transmitted from the supply device to the shelf labels by means of the signal in a rechargeable long-term accumulator, and uses the electrical energy for operating the same outside the time interval in which the signal is stored.

This object is furthermore achieved by an electronic shelf label system having shelf rails and shelf labels fastened thereto, wherein the shelf labels are configured to be supplied with energy in a contactless manner, and wherein each shelf rail has a supply device for supplying energy to the shelf labels fastened thereto in a contactless manner, and each of the shelf rails has at least one wire loop, wherein the wire loops are part of the supply device of the shelf rails, and the wire loops are used for outputting signals which can be generated by the supply device for the purpose of supplying energy to the shelf labels positioned at the shelf rails in correspondence with the wire loops, wherein the shelf labels have a rechargeable long-term energy store, and wherein the shelf labels are configured for storing in the long-term energy store energy transmitted from the supply device to the shelf labels by means of signals, and for operating the same outside the time intervals in which the signals are stored using the energy present in the long-term energy store.

Contrary to the known measures, it follows that no contact or wired energy supply of the shelf labels at the shelf rail is required at all with the measures according to the invention. This gives rise to the advantage that the energy supply of the shelf label takes place completely without mechanical contacts and the attendant problems. The system can be produced at a lower cost and can be operated practically maintenance-free on the basis of the mechanical parts, in particular, because of the avoidance of these mechanical parts, which are particularly easy to maintain.

In addition, the energy efficiency aspects in the system are also considered with the necessary attention. The signal is used for charging the long-term energy store in the case of a shelf label positioned along the relevant wire loop whenever it is output by the supply device. This measure ensures that the power required for generating and outputting the signal, which has to be provided by means of the supply device, in particular its battery, is optimally used even outside the supply device. In this case, it is contemplated that such electronic shelf label systems may have a large number of shelf rails. Thus, for example, up to 100,000 such shelf rails can be installed in a larger supermarket. Since each of these pallet rails is equipped with a supply device, in particular battery-operated, this means that 100,000 such supply devices must also be supplied with electrical power or energy at first. If the power output by means of the signal is not converted as completely as possible into energy storage on the label side of the rack receiving the signal, the energy component required by the supply device for outputting the signal is virtually "smoke-free", i.e. wasted, by the radiation of the signal.

On the one hand, the energy required for outputting the signal can be provided by means of a battery, in particular a rechargeable battery, which is installed in the supply device. With this configuration, unused radiation losses caused by the output signal lead to a shortened battery life and to increased maintenance costs, or in the case of rechargeable batteries to more frequent charging cycles, which in turn shortens the service life of the battery.

However, energy waste is to be noted even in the case of constructions in which the supply device is supplied by means of a power source which is connected on its side to a conventional power grid. Even in this case, without systematically intermediately storing or buffering the energy transferred by the signal on the side of the shelf label converted to a large number of supply devices, there is a great difference between the energy delivered into the system and the energy actually used in the system for electronic processing. In this case, as mentioned, a significant component of this difference will be assigned to the unwanted radiation of the signal.

The same applies in the sense that the supply to the supply means is also supplied by means of "WiFi power".

However, another significant advantage also arises from the storage of energy by means of signal transmission in the rechargeable long-term energy store of the shelf label. This measure allows the shelf label to be activated not only within the time interval of the presence signal, but also to be in operation completely separately from the energy supply that is currently occurring by the signal, even outside the time interval of the presence signal. This in turn forms the basis for the various new designs and possibilities of use of shelf labels which are no longer limited or restricted by the signals which usually occur as little as possible for energy-saving reasons, which are discussed in more detail below.

According to a preferred embodiment, the long-term energy store can be realized by a so-called "supercapacitor" (simply "supercapacitor (Supercap)", also called "supercapacitor"). Of course, rechargeable or secondary batteries may also be used. However, the advantage of the supercapacitor mentioned lies in the fact that. Supercapacitors (also known as supercapacitors) are high-power capacitors that have a capacitance value that is much higher than in the case of other capacitors, yet have a lower voltage limit, and eliminate gaps between the electrolytic capacitor and the rechargeable battery. The super-capacitor typically stores 10 to 100 times the energy per volume unit or mass unit of the electrolytic capacitor, can accept and output charge much faster than batteries, and tolerates much more charge and discharge cycles than rechargeable batteries. In the present application scenario, the signal may occur as little as possible for the mentioned energy saving considerations and may then also be present during as short a time interval as possible. However, with the aid of supercapacitors, such relatively short signal occurrences can also be optimally used for rapid and in particular sufficient energy storage for later operation outside the time interval in which the signal is present.

Despite the fact that small configurations are used when integrating supercapacitors into shelf labels, it should be mentioned here by way of example that at the point of time of the application supercapacitors and supercapacitors are commercially available, for example, from a large number of companies, such as AVX, cellergy, elna, ioxus, maxwell, nichicon, panasonic, powerStor.

It should also be mentioned at this point that "battery operation" of the supply device is also possible by means of the supercapacitor installed there.

Further particularly advantageous embodiments and developments of the invention emerge from the dependent claims and the following description. The features of one claim category may be further developed in accordance with the features of other claim categories, such that the effects and advantages listed in conjunction with one claim category also exist for the other claim category.

For optimal use of the signal, it is according to another aspect possible, in addition to the energy supply of one or more shelf labels fastened at the shelf rail, to construct the communication of the supply device with one or more selected shelf labels by means of the signal, and each shelf label, when storing the signal, checks if the shelf label is selected for communication with the supply device in the case of evaluating the signal. In addition to the overall energy supply to all shelf labels fastened at the shelf rail along the wire loops, this can also enable selective addressing or selective communication establishment with individual shelf labels or a group of shelf labels arranged along the wire loops.

In this case, it is advantageous if each shelf label, when a signal is present, first establishes its power supply by means of the signal and thereafter checks whether the shelf label is selected for communication with the supply device. Thereby ensuring that the energy stored in the long-term energy store is used exclusively only when the shelf label is operated outside the time interval of the presence signal. At the same time, the energy supplied by means of the signal is used for directly supplying the shelf labels for communication purposes.

In order to optimize the energy yield in storing the energy transmissible by means of the signal, it is advantageous if it is determined that each shelf label which is not selected for communication with the supply device reduces its activity to the point that the signal is used for storing electrical energy during the entire remaining time interval in which the signal is present, until the long-term energy store is charged as completely as possible. For this purpose, the electronics of the shelf label can be configured such that parts of the electronics, in particular those which are used for communication purposes and which are not required for direct use for energy storage during the entire remaining time interval of the presence signal, for example digital devices, are switched off, are currentless or at least are switched to a state with very low energy consumption.

The electronics of the shelf labels can also be designed such that the process of energy storage in the presence of a signal is independent of whether the respective shelf label should participate in communication with the supply device.

Such electronic shelf labels may provide the most diverse functionality or perform the most diverse functions by means of their electronic devices or components. For example, the shelf label may have been configured or otherwise constructed for capturing environmental parameters, such as for capturing temperature or humidity, or as an input element for receiving user input interactions (e.g., capturing a fingerprint or key operation), or as a display medium for presenting information to a user, i.e., as a shelf label display. Sensors may also be present, by means of which the distance to an object on the bottom surface of the shelf or in front of the shelf can be determined, such as so-called "time-of-flight" sensors. A camera may also be included by means of which a digital image of the product or an EAN code thereof may be generated, which may then be used to register the product or to establish a logical association between the product and an associated shelf label. However, a camera may also be used to detect a person or to identify the direction of movement of a person or the movement of his hand in front of the shelf. Identification of the person, such as identity verification and thus access to the attendant can thus also be achieved. Based on this, for example, the real tags can display information or provide interaction possibilities which are only conceivable for the service personnel or in particular for a specific class of service personnel (goods regulator, administrator, etc.).

The at least one shelf label of the system can therefore have at least one consumer (sensor, camera, input element, etc.) which causes an electrical power consumption outside the time interval of the presence signal, wherein each shelf label with such a consumer according to the method compensates the power consumption of the consumer outside the time interval of the presence signal by means of the electrical energy stored in the long-term energy store.

The one or more consumers are therefore additional components which are provided in addition to those components of the shelf label which are necessary for the contactless energy and communication supply and, if appropriate, for the display of information in the case of the shelf label being configured as a shelf label display. However, the display unit required for this purpose can also be configured as a consumer and can therefore be supplied by means of a long-term energy store.

The electrical consumers can also be powered during the presence of the signal by means of the energy stored in the long-term energy store.

It is particularly advantageous if the respective consumer processes data outside the time interval of the presence signal during its activity causing the consumption of electric power, which data have previously been transmitted from the supply device to the shelf label with the consumer during the communication between said supply device and said shelf label and stored there. This situation exists, for example, if biometric data corresponding to a service person have been previously transmitted from the supply device onto the real label and then used to identify the person (e.g. service person) by means of a camera at a later point in time when the signal is no longer present. Thus, the image content of the display unit of the shelf label can also be changed at every arbitrary point in time outside the time interval in which the signal is present, taking full advantage of the image data previously obtained from the supply device.

Furthermore, it has proven to be advantageous if the respective consumer generates data outside the time interval in which the signal is present during its activity causing the consumption of electrical power and stores the data, and thereafter, i.e. during the time interval in which the signal is present, transmits said data from the shelf label to the supply device during communication with the supply device. Such a scenario exists, for example, if a temperature profile is recorded outside the presence of a signal by means of an electrical consumer, such as a temperature sensor, or a change or removal or replenishment of an object on the bottom surface of the shelf is recognized, for example by means of a time-of-flight sensor, or a user input is captured, for example by means of an input element, etc. In all these cases, the relevant consumer generates data which, in the presence of the signal, is transmitted to the supply device at a later point in time for further processing. For this purpose, the respective consumer has a memory unit which can be accessed via a data bus from the electronic device of the shelf label provided for communication with the supply device in the presence of the signal. It would also be possible to provide a central memory unit (e.g. EEPROM) in which data can be placed centrally by the consumer and from which it can also be recalled centrally by means of the mentioned electronic device provided for communication.

The shelf labels are furthermore designed such that they can be placed on specific shelf rails. The shelf label thus has fastening elements that are configured to be substantially complementary to those of the shelf rail for interfacing force transmitting connection with the shelf rail. The embodiment is preferably rail-mounted, so that the shelf labels can be positioned freely selectively along the shelf rail and, if necessary, also freely movable along the shelf rail. There, the shelf labels are supplied with energy in a contactless manner, which is described in more detail below.

The shelf label may have a proprietary interface for energy transfer that can only be used for this purpose. However, shelf labels preferably have standardized energy transmission interfaces, which can be constructed, for example, according to the RFID standard (RFID representation Radio Frequency Identification (radio frequency identification) and applicable standard is, for example, ISO/IEC 18000, etc.). However, the shelf label particularly preferably has a first NFC interface for the contactless energy supply of the shelf label by means of a (radio) signal (NFC signal). The advantage follows that the NFC interface can be used not only for local energy transmission at the shelf or at the shelf rail, but also directly there for bidirectional contactless communication. In particular, problems in radio traffic caused by other radio systems in shops or goods sales are avoided, since these other radio systems are usually located far from the shelf where the shelf labels are installed and thus have little to no effect on the local energy transmission and on the communication between communication partners located closely to each other directly at the shelf rail. Here NFC stands for near field communication and applicable standards are e.g. ISO/IEC 13157, 16353, 22536, 28361 etc.

The shelf label may have a power saving display unit, such as an LCD display, when configured as a shelf label display. However, the technology applied is based in particular on electronic ink technology or electronic paper technology. Such display units thus have a reflective screen, which is also referred to in professional jargon as an electronic paper display, abbreviated as EPD, and is realized by means of "electronic paper" (abbreviated as "E-paper", also english "E-paper" or "E-ink"). These terms essentially represent the principle of an electrophoretic display, wherein for example positively charged white particles and negatively charged black particles are contained in a transparent viscous polymer. By applying a voltage to the electrodes for a short time, either the black particles are placed before the white particles or vice versa in the viewing direction, wherein a medium made of particles and polymer is arranged between said electrodes. This arrangement is then maintained for a relatively long time (e.g., several weeks) without other energy delivery. If the display is segmented accordingly, for example letters, numbers or images with a relatively high resolution can be implemented in order to display said information. However, such a reflective screen may also be realized by means of other techniques, which are known for example under the term "electrowetting (electrowetting)" or "MEMS". As mentioned, the screen may be configured for black and white reproduction, gray gradient reproduction, black and white and red reproduction, or black and white reproduction, for example. Future developments enabling full color or multicolor reproduction should also be included together. Such a screen is entirely generally reflective, i.e. passive, not self-illuminating, wherein the (relatively static) information reproduction is based on light (ambient light) generated by an external (artificial or natural) light source being incident on the screen and reflected therefrom to the viewer.

The display unit is supplied with energy on the one hand and with data on the other hand by means of the first NFC interface, which data may represent commands or image content for controlling the display unit. The data can thus also be transmitted via the NFC interfaces during the supply of energy via these NFC interfaces, said data being processed by the display unit in such a way that the image content of the screen of the display unit changes. After the end of the change of the image content, corresponding status information can also be output by the display unit via the NFC interface, said status information representing a successful change of the image content. After the end of the change of the image content and if necessary also after the output of the status information, the supply of energy via the first NFC interface by means of the signal can be ended, whereby the image content of the screen remains unchanged until the next desired change.

The first NFC interface also has the previously mentioned electronic device, in this case in particular a microcontroller unit, which can exchange data with the consumer via a data bus.

In addition to the NFC interface and its digital level, a central microcontroller unit can also be provided in the shelf label, which coordinates (controls) the functionality and the flow in the shelf label, but in particular also the energy management in the shelf label.

The use of the mentioned technology in particular allows the realization of shelf labels, in particular configured as shelf label displays, without their own batteries or accumulators, which are relatively expensive and require maintenance or replacement over time.

If necessary, a first capacitor, a so-called smoothing capacitor, is used in the shelf label, which is usually provided in the case of a voltage supply (in this case a so-called contactless power transfer unit) for short-term, temporary smoothing or stabilizing of the internal supply voltage.

The shelf label may also have one or more second capacitors, so-called auxiliary capacitors, which are typically distributed in the electronic device in order to locally support the supply voltage in its environment.

The shelf label is thus designed such that the electronics of the shelf label for communication, if necessary also for updating the screen content, are always active only when the shelf label is supplied by a signal by means of an external electronic supply device, with the first NFC interface being fully utilized.

The smoothing capacitor and the auxiliary capacitor allow the first NFC interface to be operated only very briefly beyond this in time when the signal is removed, until the supply voltage established via the NFC interface itself collapses. From this point in time, only the electrical energy stored in the long-term energy store is available to the consumer of the shelf label, with which the operation can be maintained for several hours until the long-term energy store has to be charged again by means of a signal (for example an NFC signal).

The housing of the shelf label can be completely and permanently enclosed, since replacement of the battery or accumulator is no longer necessary, so that the housing is only opened for recycling purposes (e.g. with special tools).

NFC functionality, such as normalizing NFC communications along with normalizing energy supply during NFC communications, may be implemented by means of commercially available NFC modules (e.g., for implementing NFC tags). Together with the display capability in question, shelf labels can thus be realized which are reduced to a small number of absolutely required electronic components and which are therefore also extremely advantageous in terms of both power properties.

The screen updating of the energy-saving display unit and the status reporting thereof are not carried out directly by the shelf label display in communication with the access point (as is the case in the case of the already existing system), but rather by an interposed supply device which acts as a relay station and is contacted on its side by the access point via a suitable (and essentially freely selectable) communication method, which is discussed in more detail below.

If a function exceeding the pure display capability is required, the shelf label is, for example, modularly equipped with the consumers required for this from the factory. The supply device then serves not only as a relay station for communication with the consumers during the presence of the signal, but also as a relay station for energy supply to the shelf labels positioned in correspondence with their wire loops, in order to enable the consumers of the shelf labels to be operated in a time-shifted manner outside the time window in which the signal (for example NFC signal) occurs, and if necessary also a display unit, for example for an internal change of the image.

As mentioned, the supply device has at least one wire loop formed at the pallet rail and an electronic supply unit which is coupled to the at least one wire loop, in particular is electrically conductively connected to both line ends (hereinafter referred to as loop terminals) of the wire loop. The supply unit is configured for contactless energy transmission by means of the wire loops to the shelf labels for powering the shelf labels, which are mounted at the shelf rail in correspondence with the wire loops. By "in a contactless manner" is meant here that this is done by generating and outputting the mentioned signal (for example an NFC signal), i.e. by signaling or by means of inductive coupling between two adjacently positioned wire loops or coils.

For receiving signals, shelf labels also have wire loops, i.e. coils, consisting of a single loop or winding or a large number of windings. The coil is an integral part of the first NFC interface of the shelf label.

Furthermore, "corresponds to" means that the shelf label is positioned adjacent to the face that is braced by the wire loop of the shelf rail and is positioned there substantially within or adjacent to the area defined by the wire loop of the shelf rail. The wire loops of the pallet track can themselves be configured, for example, visually in the plane of the pallet track or be obscured by a strip of protective material or a wall of the pallet track. If a shelf label is inserted into the shelf rail, the wire loops or coils mounted in the shelf label are automatically within the area available for transmitting signals between two side-by-side positioned wire loops or coils. In the case of shelf labels inserted into the shelf rail, the faces that are braced by the two wire loops or coils (belonging to the shelf rail on the one hand and the shelf label on the other hand) are preferably parallel and oriented to each other and positioned at a defined distance of less than one millimeter up to a few millimeters. In order to ensure, i.e. not to influence or hinder, the signal transmission towards the shelf labels and the communication between the supply device and the shelf labels, the shelf rail itself is made of a suitable material, preferably plastic, for example by injection molding. The shelf rail can have an electrically conductive, preferably metallic, particularly preferably planar shielding on its rear side, i.e. the side facing the shelf and thus facing away from the shelf label fastened thereto, which shielding allows a defined background to be produced, which allows the antenna resonant circuit required for signal transmission in the supply device to be tuned to it. Undefined background may also result in a strong detuning of the antenna resonant circuit, so that communication may even become impossible and/or energy transfer is inefficient. The defined background created by the shielding means contributes to efficient energy transfer and reliable communication.

Furthermore, at least one wire loop may optionally be integrated into or fastened at the shelf rail. It is advantageous if the carrier rail is made of plastic, for example, as mentioned, and the wire loops are already integrated there, for example, during injection molding, i.e. when the carrier rail is manufactured. However, the wire loops may also be fastened to the surface of the shelf rail, for example by means of adhesive bonding. Especially when a number of wire loops are required which are arranged side by side and accordingly a number of wires should also be considered, it has proved to be advantageous if the wire loop(s) is/are structured on a printed circuit board. The printed circuit board can then be integrated as a self-device into the pallet track or fastened thereto. The shelf rail may also be configured such that the printed circuit boards may be replaced so that it may easily react to the most diverse required profiles (Anforderungsprofile) in shelf plans with the most varied wire loop configurations, which may be implemented on a single printed circuit board or on various printed circuit boards, for example. However, the carrier rail itself particularly preferably has a wire loop receptacle. The wire loop receiver can be configured such that it is positioned, for example, on the front side of the pallet rail, i.e. as close as possible to the pallet rail in the state of the rear side of the pallet label being fastened to the pallet rail. However, the wire loop receptacles can also run on the rear side of the carrier rail corresponding to the region of the carrier rail in which the carrier label can be placed, which can lead to better accessibility to the wire loops for maintenance purposes or ensure excellent damage protection. Finally, the wire loops are also hidden there from view by the customers of the supermarket. Structurally, the wire loop receiving means can be realized, for example, by a slot-like recess in the carrier rail, for example, in a plastic material, into which the wire loop is inserted. So that the shape of the wire loop and its exact position can also be defined as precisely as possible without other measures such as the previously mentioned printed circuit board and its positioning. It is also possible to electrically connect the wire loop positioned on the rear side with the electronics of the supply device at virtually every arbitrary point, irrespective of the position of the shelf label positioned on the front side at the shelf rail. The recess may also have a snap or securing mechanism which secures the wire loop in its nominal position. The recess may also be configured such that it can receive a plurality of windings of the wire loop, wherein the windings can be arranged side by side and/or one above the other in the recess.

Furthermore, in the case of the direct integration of the wire loop receptacles into the pallet rail (i.e. into the material thereof), the wire loop is not restricted by the production process restrictions for the printed circuit board when planning or producing the wire loop, and therefore a wire loop having a length that greatly exceeds that of the printed circuit board currently of approximately one meter can also be realized. Thus, it is entirely possible to also realize wire loops extending along the entire pallet rail, which may be several meters long.

The circumference of the wire loop of the pallet track may extend, for example, along the entire length of the pallet track and the entire height of the pallet track. However, the face that is spanned by the wire loops will preferably be slightly smaller than the face of its front face defined by the physical dimensions of the shelf rail. The at least one wire loop is preferably positioned in a channel of the pallet track, which channel is configured at the back side of the lower wall of the pallet track, i.e. the pallet tag is attached at its back side or back wall to said wall in a manner inserted into the pallet track. Said channels are integrated in the wall. In order to realize the wire loops of the shelf rail, a single circumferential conductor track or a coil-shaped, multiply circumferential conductor track, i.e. a conductor track with a plurality of windings, may be provided. The wire loop has one loop terminal each at both ends thereof, to which a supply device is connected.

The shelf rail may be equipped with a single wire loop, for example, extending along substantially the entire length of the shelf rail. So that a single signal can be supplied to multiple shelf labels simultaneously. However, it may also be advantageous if a plurality of wire loops are configured along the longitudinal extension of the pallet track, which wire loops are each themselves coupled with a supply unit (as mentioned, only with individual loop terminals in this case), and the supply unit is configured for outputting signals in a loop-selective manner, i.e. for selectively transmitting energy by means of each of the wire loops. This enables a single supply device to be used for selectively supplying energy to a single pallet tag or a group of pallet tags, wherein the pallet tags are arranged in correspondence with the respective wire loops of the pallet track. Depending on the implementation, for example 2 or 3 or up to 15 or even significantly more wire loops can be implemented along the shelf rail. The wire loops are positioned side by side along the longitudinal extension of the pallet track, and the two loop terminals of the wire loops are each guided along the pallet track to the supply device and are electrically conductively connected thereto. The longitudinal extension of the region at the shelf rail covered by the respective wire loop may be the same for all wire loops. Thus, a number of zones closely spaced to each other may be defined along the shelf rail, the respective longitudinal extension of said zones facing the longitudinal extension of the shelf labels applied at the shelf rail, wherein the longitudinal extension typically has a length of a few cm, e.g. 8-12 cm. This enables separate (selective) energy supply for each shelf label and separate (selective) communication with each separate shelf label at (almost) any location along the shelf rail. It is advantageous if the positioning of the shelf labels should be as flexible as possible and nevertheless as separate energy supply or communication with each shelf label should be possible. However, a larger area may also be provided, in which then a plurality of shelf labels may be located, which are then supplied with energy together with the wire loops concerned, and either collectively supplied with data or perform separate communication with the relevant power supply, as long as a signal is present. This configuration may be desirable if the exact location of the corresponding shelf label is not critical. This is given if, for example, a plurality of identical products are placed on a shelf across a longer section or the total length of the shelf, and identical information about these products is always presented by a plurality of shelf label displays placed at a greater distance from each other along the longitudinal extension of the shelf label. However, along the shelf rail, there may also be a hybrid arrangement consisting of relatively short zones and relatively long zones as well.

The wire loops of the pallet track can all be used jointly, i.e. simultaneously, for transmitting energy from the supply device. However, this means a corresponding design or a corresponding construction for the electronics of the supply device. It has therefore proved to be particularly advantageous if the supply unit is configured for multiplexing the energy transmission through the wire loop. Here, only a single wire loop selected electronically is always used for energy transmission.

In a similar manner as already discussed in connection with shelf labels, the supply device may be configured differently in terms of its interface for energy transmission. However, the supply unit is preferably configured as a second NFC interface for contactless energy supply of one or more shelf labels, wherein at least one wire loop of the shelf rail is part of the NFC interface that is determined for contactless energy transfer (and for contactless communication). The second NFC interface may be implemented with commercially available NFC circuits (e.g., NFC reader circuits) that are connected to the wire loop.

In general terms, it can be determined here that the wire loop thus realizes an inductance which is used as an integral part of the antenna or for inductive coupling with a corresponding inductance or wire loop on the side of the shelf label.

It has proved to be particularly advantageous if exactly one individual electron supply is used for each shelf rail. This allows a focused energy supply to be achieved for only the one shelf rail, i.e. for all shelf labels fastened to the shelf rail.

In this connection, it has furthermore proved to be particularly advantageous if the electronic supply device is integrated into or fastened at the pallet track. A shelf rail with a separate electronic energy supply can thus be realized. The supply device can also be constructed, for example, directly at the printed circuit board. The supply device can furthermore be connected as a module to the printed circuit board or mechanically coupled as a module to the carrier rail, for example laterally inserted into a receiving space or receiving area provided for this purpose and electrically conductively connected to the wire loops of the carrier in a manner located there. The pallet track can thus be tolerated (vertragen) as a whole, including its supply, and can be put into use again at another location without problems.

The energy supply of the supply device can be realized in different ways. The supply device can thus take place, for example, via an ethernet cable which connects the supply device with other communication devices, for example routers, wherein the supply voltage for the supply device is also provided via the ethernet cable.

However, a separate supply station (e.g. a power supply) may also be provided for supplying energy to the electronic supply device. The supply station preferably supplies a group of electronic supply devices, particularly preferably for the entire rack, in particular for a group of racks. This allows the supply infrastructure to be built in a modular manner for individual shelves or for geographically or thematically categorized groups of shelves, or to only minimize the number of supply stations necessary.

However, the electronic supply device is particularly preferably configured to be able to be supplied with energy in a radio-based manner, and the supply station is configured on its side as a radio energy source for supplying the electronic supply device with energy, in particular in a directional manner in a radio-based manner. The energy transmission is thus targeted in a contactless manner towards the supply device by means of a wireless energy source. The supply device has a supply receiver for receiving a radio signal of the transmission energy. This enables a completely cable-free supply infrastructure of the supply device, which is fastened on the one hand to the pallet labels at the pallet track and on the other hand is provided for supplying the pallet labels. In effect, the installer of the system saves cabling between the actual energy source and the corresponding racks. This enables a substantially free selective positioning of the shelves in the store and a free selective and simple positioning of the shelf rails at the various shelves and their exchange between the shelves. This type of energy transfer and the technology on which it is based are known in the term "WiFi powered". A radio energy source equipped with such a technology can be installed, for example, at the ceiling of a commercial site and selectively supply the supply devices allocated there to the respective pallet rails and positioned in this circumference within a circumference of up to a maximum of 10 meters by means of powerful, i.e. focused radio signals which are set towards the supply devices.

As already mentioned, the electronic supply device is preferably also configured for contactless communication with one or more shelf labels, taking full advantage of the technology that is also used for transmitting energy to the shelf labels. The already mentioned NFC technology is preferably used again in this case. This allows the best possible exploitation of the available electronic components for contactless energy transmission as well as contactless communication over relatively short distances, as is the case with shelf labels fastened at the shelf rails.

The supply device can now be configured such that, when there is an energy supply by means of the radio energy source, it also generates and outputs a signal in order to supply energy in a contactless manner to the shelf labels located in correspondence with the wire loops of the shelf rail even during the time intervals of the energy supply by means of the radio energy source. However, in order to enable the energy supply of the shelf label also outside the time interval in which the energy supply by the radio energy source is present, it is advantageous if the supply device has a supply energy store. The supply energy store (diese) may be a rechargeable battery or accumulator or the mentioned supercapacitor. The supply energy store is coupled to the charging electronics of the supply device, wherein the charging electronics can be part of the supply receiver or can be configured to be connected to the supply receiver separately therefrom. For example, the charging electronics, which can be realized as a commercially available module, are designed such that, when a radio signal is received from the radio energy source, the supply energy store is charged by the charging electronics, and if necessary a supply voltage is also output which is then available.

By means of the supply energy store of the supply device, it is now possible to complete the operation of the electronic equipment of the supply device itself on the one hand and the energy supply of the shelf labels at the shelf rail on which the supply device is mounted on the other hand, separately (also time-shifted) from the time of the radio activity of the radio energy source. Thus, for example, an operating scenario can be implemented in which the supply energy storages of the various supply devices are charged, for example, during the night time by means of a wireless energy source, in order to supply the shelf labels with energy by means of signals whenever required during the day. In the case of corresponding demands, the supply device can also be supplied with energy in a targeted manner during the day, in order to recharge its own supply energy store on the one hand and/or also supply the shelf labels with energy from the respective supply device by means of signals. This may be of interest if autonomous energy supply of the supply device is not ensured during the day, once-down night charging, caused by increased activity in one or more shelf labels.

In addition to the second NFC interface, which is provided for the energy supply of the shelf label and for the communication with the shelf label, the supply device has a further interface, which is determined for the communication with the access point. The other interface may be configured for radio communication. A time slot communication method, in particular a proprietary time slot communication method, may preferably be applied for radio communication with the access point.

According to such a proprietary slot communication method, the communication station (here the access point) communicates with a plurality of supply devices by means of a slot communication method, wherein a plurality of slots are prepared for communication in succession (IN SICH STETIG widerholender Folge) continuously repeated for each slot cycle and each slot is represented in an unambiguous manner by an unambiguous slot symbol and can therefore be distinguished from other slots only by a slot symbol. According to the method, the access point transmits a synchronization data signal with a slot symbol at the beginning of the corresponding slot for the currently existing slot. The supply device is configured to transition from the sleep state to the active state at a wake-up time point and to receive the synchronization data signal in the active state, and to define a new wake-up time point corresponding to a next occurrence of a time slot determined for the supply device in a time slot period subsequent to a currently existing time slot period if the received time slot symbol indicates the time slot determined for the respective supply device.

The advantage follows that the synchronicity between the access point and one of the supply devices is recognized in a manner that is as simple as possible and nevertheless extremely robust, is maintained and ensured during the operation of the system. Since the checking of the synchronicity already takes place immediately at the beginning of the time slot, this also improves the energy efficiency of all the supplies which are logically assigned to the individual access points.

It is entirely sufficient here that each supply device participating in the communication with the associated access point knows by means of the slot symbols which indicate the slot determined for said supply device. Each of the supply devices is thus individually oriented to the occurrence of a slot symbol associated with the supply device, identifies the slot symbol associated with the supply device and defines its next wakeup point in time in order to be synchronized with a Timing (Timing) of the slot communication method, which is predefined by the communication station, wherein the Timing is known to the supply device. It is entirely sufficient here for the slot symbols to explicitly identify the respective slots, for example with a slot identifier that is separate for each slot. Other information encoded into the synchronization data signal (and thus as often as this happens in other methods) is not necessary here in order to operate the provisioning device in synchronization with the access point to which it is allocated in radio technology. The synchronization of the supply device with the access point is thus determined by the relevant supply device solely by identifying the situation of the slot symbol which occurs at the point in time or in the expected time window expected by the supply device and which indicates the slot determined for the supply device.

After the supply device has determined its synchronicity as previously discussed, it is in principle sufficient if the supply device again changes into a sleep state, since the next wake-up time point is automatically known by the time frame of the slotted communication method, which is known to the supply device. The definition of a new wake-up time point may thus be limited to the supply device's e.g. time control stage (e.g. timer) being restarted with the timing parameters that have been used previously in the transition from the sleep state to the active state. Thereafter, the supply device can again change to the sleep state and remain there until the wake-up and the change from the sleep state into the active state are again carried out in the next time slot cycle at a new wake-up point in time in a manner triggered by the time control device. However, the supply device does not necessarily have to remain in a sleep state for the remainder of the time slot determined by the supply device, but may also perform other tasks in an active state during the time slot or the time slot cycle. The time control device previously discussed then works in the background independently of the various other activities of the supply device. The new wake-up time point may be defined by determining an absolute or relative time specification, such as with respect to the point in time when the synchronization data signal occurs or with respect to the point in time when the sleep state is again taken after the active state, or with respect to the point in time starting at the end of the synchronization data signal. However, the definition of a new wake-up time point can also be understood such that the duration of the sleep state immediately following the active state or the sum of the durations of the sleep state and the active state or the sum of the durations of a plurality of such state sequences determines the new wake-up time point, in which the slot symbol is received.

Since each supply device runs its own time control stage and an exemplary dispersion of the behaviour of the corresponding electronic component cannot be excluded (Streuungen), defining a new wake-up time point may also involve compensating for the drift of its time base that exists separately for each supply device. For this purpose, the time difference between the expected and the actual occurrence of the synchronization data signal with the time slot symbols, which indicate the time slots determined for the respective supply device, can be measured, for example, in the supply device and taken into account at the time control stage for correcting its timing. However, compensation is only used when the synchronicity is determined.

However, if additional slot symbols are received instead of the intended slot symbols, there is no synchronization and the provisioning apparatus must perform new synchronization. For this purpose, such an asynchronous supply does not change periodically as would be the case in the synchronous state, but changes from its sleep state to its active state once at any point in time and remains in this active state in preparation for reception, for example. If nothing is received within a certain time interval, such as the duration of a time slot, the provisioning apparatus again transitions to a sleep state and repeats the reception attempt at another point in time. Once the synchronization data signal is received, the time slot symbols are evaluated, i.e., checked. The slot symbols received here indicate with the highest probability the slots that are not determined for the associated supply device, which is determined autonomously by the supply device. The supply device knows the systematicness of the occurrence of the slot symbols and can independently decide after evaluation of the received slot symbols whether the supply device can consider the slot determined for it in the still existing slot cycle (first case) or in the subsequent slot cycle (second case). For the first case, the supply device is configured to define a new wake-up time point in the currently existing slot cycle, which corresponds to the next occurrence of a slot determined for the supply device. By evaluating the received slot symbols and knowing the systematicness of the occurrence of the slot symbols, the supply device determines that the slot determined for the supply device will still occur in the currently existing slot cycle. For the second case, the supply device is configured to define a new wake-up time point in that slot cycle following the currently existing slot cycle, which corresponds to the next occurrence of a slot determined for the supply device. By evaluating the received slot symbols and knowing the systematicness of the occurrence of the slot symbols, the supply device determines that the slot determined for the supply device will no longer occur in the currently existing slot cycle, since the slot has occurred in the past in this slot cycle. As discussed at the beginning with respect to the synchronization state, the time control means described for this type of definition of the new wake-up point in time are also used, wherein the time control means are now run with that timing parameter which is utilized to achieve the desired entry into the synchronization state. The timing parameters to be selected are derived for the supply device from the intrinsic knowledge of the slot communication method applied. The timing parameters are thus determined by the electronics of the supply device, which have knowledge about the parameters of the slot communication method.

These parameters may be queried by the provisioning device from the access point when the provisioning device registers at the corresponding access point, or transmitted to the provisioning device, or may have been entered into the provisioning device in advance as a program. In both cases, it is expedient if the supply device has a memory stage for storing the parameters of the slot communication method and is designed to access and take into account these parameters for the purpose of defining a new wake-up point in time. The parameters may represent all details of the timing of the slot communication method, such as for example parameters related to the time flow for communication between the access point and the provisioning means, parameters related to predefined points in time or time segments and parameters related to the basic structure of the slot communication method, such as the number of slots, the duration of the slot period, or as parameters may represent explicitly specified slot symbols for identifying the respective slots or algorithms for calculating the slot symbols. By means of these parameters, the asynchronous supply device can autonomously, i.e. automatically itself without external assistance, ascertain that the time slot determined for the supply device or whether the time slot determined for the supply device already belongs to the past in the existing time slot period can be expected based on whether the time slot symbol just received is still in the currently existing time slot period, and that the next time slot determined for the supply device will therefore only occur in the next time slot period. In the active state, the supply device in question calculates a new wake-up point in time, transitions to the sleep state and, at the calculated wake-up point in time, transitions into the active state, receives the slot symbols of the slots determined for the supply device and is then again in the synchronized state. As soon as no further activity is expected by the supply device in the time slot present, the supply device immediately shifts to the sleep state and then shifts to the active state again in the next time slot period in order to receive a synchronization data signal in the time slot determined for the supply device.

For communication with an access point, such a provisioning device basically has a radio communication stage (also called transceiver) and a logic stage interacting with it, which provides the logic functions of the provisioning device. A transceiver is an electronic device that is configured not only for reception but also for transmission, and in which the required functionality for modulating a carrier signal and demodulating a received signal is configured. The transceiver may be implemented by active and passive electronic components or assemblies by means of which analog signals may be converted to digital signals and vice versa.

For example, the logic level may be implemented entirely in hardware, or include a microprocessor and memory means or a microcontroller with integrated memory means so that software stored in the memory means may be executed. The supply device can receive radio signals from the access point by means of its transceiver, process the received data contained in the radio signals by means of the logic stage, and if necessary generate response data by means of the logic stage and output said response signals again as radio signals to the access point by means of the transceiver.

As already discussed, such a supply device has a supply energy store for its own energy supply and for the energy supply of the shelf label. In order to operate as energy-efficient as possible, the supply device has various operating states. Said active state with a relatively high energy consumption belongs to this. The active state exists, for example, when data is transmitted or received when communicating with an access point, or when the shelf label is supplied with energy by means of a signal and then also when data is transmitted and/or received when communicating with the shelf label, or when a battery voltage measurement is made of the voltage that can be generated by means of the supply energy store. While there is a relatively low energy consumption in the sleep state. So that as many electronic components as possible are preferably operated separately from the supply of current through the supply reservoir or shaded, or at least in a mode with as low an energy requirement as possible (e.g. clocked as slowly as possible). The active state is mainly present for detecting synchronicity with the access point and for communicating with the access point in a time slot determined for the provisioning means. In the active state, the supply device has, for example, a reception preparation for receiving commands and, if appropriate, also reception data from the access point and processes them by means of its logic level. In the active state, transmission data can also be generated by means of the logic stage and transferred to the communication station. Outside the time slots determined for the supply device, the supply device is operated mainly in a power-saving sleep state. In the sleep state, the logic or time control stage performs only those activities that are needed for the timing for a timely wake-up, so that the supplying device is ready to receive a synchronization data signal and/or communicate with the access point at the next time slot determined for said supplying device.

It should also be mentioned here by way of example that m time slots, for example 255 time slots, are used in the case of a proprietary time slot communication method, for example in n seconds, for example 15 seconds. n seconds constitute one slot cycle. In this time slot communication method, there are thus m time slots available for communication with the supply device within one time slot period. Each of the supply devices is assigned to one of the time slots, wherein a plurality of supply devices may also be assigned to a particular time slot.

In order to operate as energy-efficient as possible, i.e. to minimize the energy consumption of each supply device, the basic operating strategy for each supply device is therefore to keep the synchronous supply device in a sleep state for as long as possible, and to operate the synchronous supply device in an active state only in as short a time interval as possible, if absolutely necessary, such as on the one hand for the purpose of data transmission with the access point and on the other hand for the purpose of outputting a signal to the shelf label for the purpose of transmitting energy thereto and also for communication with the shelf label if necessary. This, together with the previously discussed as complete energy storage at the shelf label, i.e. as little energy as possible is lost due to unused signal radiation once the signal is present, results in an energy efficiency of the system, in particular the inclusion of its contactless components (supply means and shelf label).

In principle, however, communication protocols based on standard or normative ZigBee, bluetooth or WiFi etc. can also be applied for radio communication with the access points, which however results in less energy efficient operation of the system.

The supply device thus implements a contactless "gateway" or relay station for all shelf labels mounted on the relevant shelf rail, both for energy transmission and for communication transmission between the shelf labels and the respective access points to which the supply device is assigned in a radio-technical manner.

The access points serve as a superior interface between shelf labels of an IT infrastructure controlling the shelf labels, such as servers with corresponding software applications, cloud solutions, etc. In such a radio-based system, a set of shelf labels is allocated to such an access point by means of a corresponding supply device in a radio-technical manner (logically) such that communication with the set of shelf labels takes place exclusively via the access point. A plurality of such access points may be installed in a place of business, for example a supermarket, wherein each access point is adapted to communicate with a supply device logically (radio-technically) allocated to said access point. The access points may communicate with shelf labels grouped at the shelf rails of the respective supply devices across the supply devices, which are positioned in a geographic (radio-technology reachable) area surrounding the access points.

In addition to this functionality, the access point can also have a supply station which is designed to supply the electronic supply device with energy in a directional, radio-based manner.

In summary, the supply device in the case of the relevant pallet track implements a combined energy supply and communication supply device for pallet labels fastened at the relevant pallet track. The supply device is thus configured or constructed for local contactless energy transmission and local contactless communication with a shelf label fastened at the shelf rail.

Such a supply device may also be referred to as a shelf rail control device or shelf rail controller, since it controls all the activities of the shelf labels mounted at the relevant shelf rail, which, depending on the configuration of the shelf labels, includes not only the display behavior, the communication behavior but also the corresponding energy supply and the operation of the other consumers of the shelf labels.

It has furthermore proved to be particularly advantageous if the electronic supply device is configured for receiving and forwarding a unique identifier of a shelf label involved in the communication for the purpose of determining the position of the relevant shelf label.

If a plurality of shelf labels are arranged within the wire loop of the shelf rail or if a plurality of shelf labels are simultaneously supplied with energy through a single wire loop, precautions must be taken in order to ensure receipt of the respective identifiers. For this purpose, the shelf label may for example be programmed such that it outputs its identifier at randomly selected points in time (single or multiple times) within a time window in order to ensure individual reception at the supply device. Also in the case of such contactless transmission, anti-collision methods known from RFID technology, for example, can be applied in order to ensure individual reception at the supply device.

The unique identifier is preferably forwarded to a data processing device, such as a server at a business location, which performs or coordinates the communication with the individual electronic shelf labels.

The server may also store a logical association between the products erected on the respective shelves and shelf label displays positioned there and thereby ensure that the respective shelf label displays present those information pertaining to the relevant products.

The server may also be informed of the location or extension of the respective wire loop at the shelf rail and may also be informed by the supply means together with the identifier which wire loop has been used to derive the identifier from the shelf label. So that a three-dimensional digital map of the locations of all shelf labels in the business can also be created. This relates both to the shelf label configured for displaying information and in a similar manner to the other mentioned functionalities of the shelf label which are possible by different consumers.

The electronics of the various devices of the system, their interfaces and the like can be implemented in discrete and integrated manner by means of a wide variety of passive and active electronic devices. A microprocessor or microcontroller with corresponding peripheral components is preferably used, whereby software for providing the various functionalities is executed. So-called ASICs (application specific integrated circuits) may also be applied. In particular, the various components or groups of functions, in particular consumers in shelf labels, can have, in addition to the passive components, the individual integrated circuits mentioned (microcontrollers, microprocessors, ASICs, etc.).

These and other aspects of the invention will be apparent from the drawings discussed below.

Drawings

The invention is elucidated in more detail again with reference to the embodiments described hereinafter with reference to the accompanying drawings, to which, however, the invention is not limited. Here, in different drawings, the same components are provided with the same reference numerals. In a schematic way:

FIG. 1 illustrates an electronic shelf label system according to the present invention;

FIG. 2 shows a block diagram of a shelf rail with a supply device;

FIG. 3 shows a block diagram of a shelf label display;

FIG. 4 shows a perspective view of a shelf rail with a supply device;

FIG. 5 shows a cross section along section A-A according to the view of FIG. 4;

FIG. 6 shows a cross section along section B-B according to the view of FIG. 4;

FIG. 7 shows a view of a shelf rail with a supply device inserted only partially;

fig. 8 shows a view similar to fig. 7 with a contact element of the supply device;

fig. 9 shows a detail of the long term accumulator of the shelf label.

Detailed Description

In fig. 1a shelf label system 1 is shown, comprising a plurality of electronic shelf labels 201-211 fastened at three "smart" shelf rails 3. Each shelf rail 3 has an electron supply 401-403 which is inserted laterally into the shelf rail. Also shown is a data processing device which is realized by means of a server 5, which server 5 is connected in a cable connection to an access point 6, which has, for example, two antennas 7.

The supply means 401-403 are shown in radio contact with the access point 6 via a first radio signal F1. The image content of the shelf labels 201 to 211, which are configured as shelf label displays, can thus be changed from the server 5, if necessary, the associated status information can also be queried from the shelf labels 201 to 211 and transmitted to the server 5, or the activity of additional consumers of the shelf labels 201 to 211 (which consumers are still discussed below with reference to fig. 3) can also be controlled or used. An extremely energy efficient proprietary time slot communication method discussed in the general description is used for this communication.

Each of the pallet rails 3 is fitted at its front edge at a separate pallet bottom surface 8. All three shelf bases 8 shown belong to a shelf 9 which is only very schematically indicated. Various products can be stored on the shelf bottom 8, which products are however not shown in this case for reasons of clarity.

The supply devices 401-403 are each schematically shown at the right edge of the pallet track 3, however this is not necessarily so. The supply device can thus also be located at other positions along the pallet track 3 or also at its left edge. In this case, the supply devices 401-403 are integrated in the pallet track 3, i.e. for example mounted or inserted in a slot (not shown here, but see fig. 5).

Fig. 1 furthermore shows in each case a single wire loop L integrated into the pallet track 3, which is connected with its two loop terminals C to the supply devices 401 to 403 mounted there. The shelf rail 3 carries shelf labels 201-211.

As with the pallet labels 201 to 211, the pallet track 3 is designed such that the pallet labels 201 to 211 can be inserted into the pallet track 3 from the front and in this case locked to the pallet track 3 by means of a snap-on mechanism, so that the pallet track can only be removed again from the pallet track 3 with great effort. At the same time, the mentioned mechanism allows the shelf labels 201-211 to be moved along the shelf rail 3 with only a small effort compared to this and can thus be easily placed at any position. A snap mechanism of the described type is for example known from WO2017/153481A1, fig. 2. However, the mechanism may also be configured differently, as will be discussed in more detail below.

A block diagram of shelf labels 201-211 is discussed below with respect to fig. 2. Since it is assumed in this case that all shelf labels 201-211 are identically constructed, reference is made below only to a single shelf label 201.

The block diagram shows a first NFC interface 11 with its coil 12A connected to the interface circuit 11A. The coil 12A together with the interface capacitor 12B forms an antenna resonance circuit 12C, by means of which signals of NFC-capable devices can be received. In this case, the NFC-capable device is a provisioning apparatus 401-403, which is configured to be NFC-capable. If the coil 12A is correspondingly positioned close to (a few tenths of a millimeter to about 4 millimeters) the wire loop L, which is the case in the case of shelf labels 201 positioned at the shelf rail 3, the signals emitted by means of the wire loop L can be received by means of the antenna resonance circuit 12C and used in the shelf labels 201 for energy supply and for bi-directional communication with the relevant supply means 401-403.

For this purpose, the shelf label 201 has a so-called contactless power transfer unit 11B connected to the antenna resonance circuit 12C, which contactless power transfer unit 11B has a rectifier unit 11C on the input side and a voltage regulator unit HD on the output side. In the presence of a signal, a first supply voltage VCC1 is thus generated with respect to the first reference potential GND1, which has a value of approximately 2.2 volts, for example, and is provided for the NFC functionality of the shelf label 201.

The first NFC interface 11 furthermore has a communication unit 11E, by means of which communication can be performed in accordance with the NFC specification or protocol. The first NFC interface has a load modulation unit 11F connected to the antenna resonant circuit 12C for load modulating the received signal in dependence of the transmit data signal TX. The other component is a protection unit 11G, which is likewise connected to the antenna resonant circuit 12C, prevents an undesirably high input power and is designed as a signal limiter. Further, a clock generator unit 11H connected to the antenna resonance circuit 12C is provided, which generates a system clock CLK based on the received signal, which is used in the communication unit 11E. The ASK demodulation unit 11I (ASK stands for "amplitude shift keying-SHIFT KEYING" here) which generates the reception data signal RX from small fluctuations in the amplitude of the signal rectified by means of the rectifier unit 11C, constitutes another component. Furthermore, a digital control unit 11J is provided, which is clocked with the system clock CLK and processes the incoming received data signal RX and converts it into data D and generates the outgoing transmitted data signal TX from the data D.

The block diagram also shows a display unit 13A divided into an electronic paper display controller 14 and an electronic paper display screen 15 controllable therewith. By means of the controller 14, the received data D are interpreted, if necessary, the image content of the screen 15 is correspondingly changed or status information is output in the form of data D via the first NFC interface 11 to the respective supply 401-403.

In this case, the shelf label 201 has other consumers, i.e., an input unit 13B, a time-of-flight sensor unit 13C, a temperature sensor unit 13D, and a camera unit 13E, in addition to the display unit 13A. Like the display unit 13A, each of these units may have its own controller Integrated Circuit (IC).

The central microcontroller unit 13 constitutes a further consumer, which centrally controls the data traffic of the data D and the functionality of the shelf label 201. The data processing or control takes place here according to a program code which is stored in the microcontroller unit 13 and is executed with its Central Processing Unit (CPU).

All these consumers 13, 13A-13E are or can be determined for being operated separately in time from the presence of a signal by means of which the first supply voltage VCC1 is generated as discussed.

For this purpose, the shelf label 201 has a long-term energy storage unit 13F, which is divided into a long-term energy storage in the form of a supercapacitor 13H and a charging stage 13G, which is designed to charge the supercapacitor 13H, wherein in the presence of a signal, electrical energy is stored in the supercapacitor 13H by means of the charging stage 13G for operating the consumers 13, 13A-13E outside the time interval in which the NFC signal is present. The charging stage 13G is connected on the input side to a first supply voltage VCC1 with respect to a first reference potential GND1, i.e. to the output of the contactless power transfer unit 11B. The charging stage provides a second supply voltage VCC2 on the output side with respect to a second reference potential GND2, wherein the first and second reference potentials GND1 and GND2 are identical, i.e. the corresponding circuit points are connected to one another.

The two supply voltages VCC1 and VCC2 may be different or identical in terms of their values, which ultimately depend on the specifications of the consumers 13, 13A-13E to be supplied.

As soon as the second supply voltage VCC2 is sufficiently high, the consumers 13, 13A-13E start to operate and are functionally available.

In this connection, however, it has proven to be particularly advantageous if the long-term energy store unit 13F is configured in a controllable manner by means of the central microcontroller unit 13. Thus, for example, the energy level of the stored energy (for example, classified into three value ranges, for example, good, medium, low) can be forwarded to the microcontroller unit 13 by means of the energy states (signals) ES, and according to this the voltage supply for the different consumers 13A-13E can be controlled optionally by means of the output release control signal OE output by the microcontroller unit 13 to the long-term energy storage unit 13F, which is discussed in detail in connection with fig. 9.

Even though it is assumed in this discussion that the shelf labels 201-211 all have the same construction, i.e. all have the consumers 13, 13A-13E shown in fig. 2, this should not necessarily be so, in this regard. Thus, for example, only a few shelf labels, such as 201, 203, 204, 206, 207, 209 and 211, may be implemented as shelf label displays for each shelf rail. Other shelf labels, e.g. 202, 205, 208 and 210, may not have a display unit 13A at all, but for this purpose may have a camera unit 13E and one time of flight sensor unit 13C each, and finally the remaining shelf label 209 may ultimately have only a temperature sensor unit 13D. In principle, however, each combination of consumers 13A to 13E can be provided for each shelf label 201 to 211. This can be achieved by constructing the respective consumers 13A-13E in the respective shelf labels selectively based on hardware. This can also be implemented such that some or all types of consumers 13A-13E are implemented and can be turned on by means of control commands, i.e. software-based (for example by means of the central microcontroller unit 13) can be activated and/or the housing of the respective shelf label 2A-2K is made available or just unavailable by special construction.

A block diagram of one of the pallet tracks 3 according to fig. 1 is discussed below with reference to fig. 3. Since all supplies 401-403 are identically constructed, shelf label 403 is typically visualized here.

The pallet rail 3 carries wire loops L fastened directly at the pallet rail, which have been integrated into the pallet rail. Corresponding to the position of the wire loop L, the shelf label displays 207-211 positioned there in this case are shown in a simplified manner. Unlike fig. 1, the electrical connection of the ring terminal C with the electronic circuit 18A of the second NFC interface 18 of the supply device 4 is also shown. The second NFC interface 18 also has similar components to the first NFC interface 11A, wherein the basic difference here is that it is designed to generate and output signals, i.e. has a transmitting unit (not shown in detail). The second NFC interface 18 also has its own NFC controller (not shown). The second NFC interface 18 is designed by means of signals output by the second NFC interface for contactless transmission of electrical energy to the shelf label displays 207-211 and for two-way communication of data with the shelf label displays 207-211 activated by the energy transmission.

The supply device 403 furthermore has an access point communication interface 19 which is designed to communicate in a radio-based manner with the access point 6 shown in fig. 1 via the first radio signal F1. For this purpose, the access point communication interface 19 has an electronic device (not shown in detail) constructed therefor and an antenna configuration 19A, which may also comprise a plurality of antennas. The supply device 403 has a control unit 20 for controlling the internal flow and the energy supply of the shelf labels 207-211 and the communication with the shelf labels 207-211 and with the access point 6. The control unit 20 is realized by means of a microcontroller which is connected to the second NFC interface 18 and the access point communication interface 19 via a bi-directional data bus.

As can be seen in the overview with fig. 1, the individual supply devices 401-403 are supplied with electrical energy by means of a supply transmitter 21 (also referred to as a radio energy source) which is configured for transmitting electrical energy to a receiver (i.e. one of the supply devices 401-403) by means of a focused or directed (second) radio signal F2 having a specific transmission power, such as 5W. Such a supply transmitter 21 also has a large number of antennas 22 (six are shown here), by means of which the direction of the energy transmission (ultimately the propagation of the second radio signal F2) can be adjusted relatively accurately so that the second radio signal F2 transmitting energy arrives exactly at the respective supply means 401-403. Such energy transfer is also known under the term "WiFi powered over WiFi". It should also be mentioned at this point that the provisioning transmitter 21 may also be installed in the access point 6.

In order to be able to use this type of energy transfer, the supply device 403 shown in fig. 3 has a supply receiver 23 adapted to receive the second radio signal F2, which supply receiver is equipped with its antenna configuration 24, which may have a plurality of antennas, and an electronic device (not shown in detail). The supply receiver 23 is designed to receive the second radio signal F2 and store the energy transmitted in this way in an internal, rechargeable electrical supply energy store 25 (for example a rechargeable battery, accumulator or "supercapacitor") and thus generate a third supply voltage VCC3 with respect to the third reference potential GND 3. Each of the power supply devices 401-403 is operated with the third power supply voltage VCC3 provided internally.

In operation, the supply device 403 can, for example, check or monitor the state of charge of the internal supply energy store 25 by means of its control unit 20. Once the state of charge falls below a certain level, the control unit 20 may request (re) charging by means of the first radio signal F1. In the mentioned proprietary time slot communication method this may occur for example in the context of a status query by the access point 6. The result of this status query is received by the access point 6 and may be forwarded directly to the provisioning transmitter 21 or, in case of inclusion of the server 5, to the provisioning transmitter 21, depending on the implementation. Since the exact geographical location (three-dimensional coordinates) of each of the supply devices 401-403, and its unique identifier, is known in the system 1 (e.g. server 5), the supply transmitter 21 can transmit the second radio signal F2 precisely aimed towards the location of the respective supply device 401-403 requesting charging. Where the second radio signal F2 is received and the energy transmitted by means of said second radio signal is used for charging the internal supply energy store 25 therein. This may also occur, in particular, when the rest of the electronics of the supply device 403 are in a sleep state.

The "intelligent" pallet track 3 described herein is thus configured by means of the supply devices 401-403 installed in the pallet track for contactless communication with the pallet tag displays 201-211 installed at the pallet track and the access points 6 assigned to the pallet track in a radio-technical manner. Furthermore, the shelf rail 3 is designed for providing energy in a contactless manner in the sense of energy storage in the supply devices 401 to 403 installed in said shelf rail thereof, for its own operation and for the energy supply of the respective shelf label display 201 to 211, and also during the time when the respective first NFC interface 11 is active by means of a signal. Furthermore, the shelf labels 201 to 211 are designed to autonomously supply their individual consumers 13, 13A, 13B to 13E with energy even during time intervals in which no signal of the respective supply device 401 to 403 is present or not present.

In operation of the system, the access point 6 may communicate image update data to the shelf label display 201, for example, by means of a proprietary time slot communication method. The associated provisioning means 401 transitions from a sleep state to an active state at its wake-up point in time, recognizes its synchronicity with the access point 6, and in succession (in Folge) recognizes that said provisioning means are addressed by the access point 6 for receiving image update data. Subsequently, in a time slot (or a series of such time slots) set for the supply apparatus 401, the image update data is transmitted to the supply apparatus 401 and is intermediately stored at least temporarily. Thereafter, the electronic components of the supply device 401 required for communication with the access point 6 are put into the sleep state again.

The provision means 401 may forward the image update data to the relevant shelf label display 201 in real time (i.e. in synchronization with the communication with the access point 6) or time offset from the reception of the image update data (i.e. asynchronously with the communication with the access point 6). To this end, the supply device activates its second NFC interface 18, generates and outputs a signal via its wire loop L, which activates the shelf labels 201-203 mounted at the uppermost shelf rail 3, establishes a communication connection with the shelf label display 201 and transmits image update data to the shelf label display 201, where the received image update data is forwarded to the display unit 13A and processed there to change the image content. During this entire process, all shelf labels 201-203 mounted at the uppermost shelf rail use this signal to charge their long term storage 13H. Upon completion notification from the shelf label display 201 to the supply device 401, the supply device stops outputting signals and all shelf labels 201-203 mounted at the uppermost shelf rail 3 deactivate at least their first NFC interface 11 with the cancellation of the energy transfer. Other activities of the consumers 13, 13A-13E of the respective shelf label 201-203 do not suffer from this deactivation and are continued by supplying energy by means of the long-term energy store 13H.

The mechanical structure of the pallet track 3, which also contributes to energy-efficient operation of the system, is discussed later.

Fig. 4 shows a shelf rail 3 with one of the shelf labels 201-211, which is configured as a shelf label display 2 and at which the shelf label is fastened. Fig. 4 furthermore shows supply devices 401 to 403 which are inserted laterally into the pallet track 3, here designated by the reference numeral 4 in an abbreviated manner. The shelf rail 3 illustratively has a length of about 3 meters, a height of about 4.5 cm, and a thickness of 1.2 cm.

Fig. 5 shows a section through the pallet track 3. According to the section A-A drawn in fig. 4, said section extends transversely (perpendicularly to the front side of the pallet rail 3) through the pallet rail 3. Furthermore, unlike fig. 4, the front part of the pallet base 8 is visible, at which pallet rail 3 is fastened by means of a cap rail (Hutschiene) 26 made of metal. The cap-shaped guide rail 26 constitutes an electrically conductive structure for producing a defined damping ratio for contactless energy transmission from the supply device 4 to the shelf label display 2 and for contactless communication between the supply device 4 and the shelf label display 2. Since the antenna resonance circuit of the supply device 4 is tuned to these defined damping ratios, by means of the defined damping ratios, on the one hand the energy transmission can be optimized and on the other hand the communication can also be performed in a reliable manner. The cap-shaped rail 26 can be connected to the pallet floor 8 by means of gluing, riveting, clamping, plugging or screwing, etc., which are not discussed in more detail in the figures.

The shelf rail 3 has a first fastening structure for fastening the shelf label display 2. The first fastening structure has a wall 29 extending between the top area 27 and the bottom area 28 of the shelf rail 3. Similar to the top and bottom regions 27, 28, the wall 29 also extends along the entire shelf rail 3 and forms a shelf label plane at its wall front side oriented towards the shelf label display 2, at which shelf label plane the shelf label display 2 is attached with its rear wall substantially flush. The first fastening structure has, in addition to the wall, a first fastening groove 30 which is formed at the top region 27 and extends along the top region 27 and a second fastening groove 31 which is formed at the bottom region 28 and extends along the bottom region 28. The fastening slots 30, 31 are configured such that the shelf label 2 can be inserted with its fastening elements 32, 33 in a locking manner into said fastening slots, such that the rear wall of the shelf label 2 is positioned in such a way that it is attached at the shelf label plane. The fastening elements 32 and 33 are positioned and configured accordingly, and the housing of the shelf label 2 is sized or shaped.

The pallet track 3 furthermore has a second fastening structure for fastening the wire loops L. The second fastening structure also has a wall 29, wherein two tubes 34 are configured at the rear side of the wall. The two tubes 34 are oriented parallel to one another and extend along substantially the entire length of the pallet track 3 positioned at a defined distance from one another of about 1 cm. The two central axes of the tube define a wire loop plane that extends parallel to the shelf label plane by a defined first distance of about 5 millimeters. The wall 29 here has a thickness of about 2mm and the tube 34 is at least partially embedded in the wall 29, which allows a small distance between the wire loop plane and the shelf label plane without unnecessarily tolerating the load of the wall 29.

The pallet track 3 furthermore has a third fastening structure for fastening the cap track 26. The third fastening structure has two substructures which are formed on the top side in a suspension device 35 for suspending the pallet rail 3 and on the bottom side in a snap lip 36 for snap-fitting.

The third fastening structure furthermore has a first spacing element 37 positioned at the top region 27 and a second spacing element 38 positioned at the bottom region 28. The two spacer elements 37 and 38 serve to fix and adhere to a defined second distance of the cap rail 26 from the wire loop plane, wherein a substantially parallel orientation of the planar structure of the cap rail 26 relative to the wire loop plane is also achieved here. The two spacer elements 37 and 38 are oriented at an angle of substantially 90 ° away from the rear side of the wall and extend from the wall 29 towards the cap rail 26, where they contact the cap rail 26 and ensure the nominal position. In this case, the cap rail 26 is positioned at a second distance of about 7 mm from the wire loop plane. The cap rail 26 itself has a thickness of about 1 mm. The height of the cap-shaped rail is approximately 2.5 cm, whereby the edge of the cap-shaped rail, which is still approximately 5 mm long on the top side and on the bottom side, respectively, is extended with a cap-shaped indentation of approximately 3mm, with which the interaction with the plastic body of the shelf rail 3 takes place. The length of the cap-shaped rail 26 corresponds approximately to the length of the shelf rail 3.

Furthermore, the external expansion of the coil 12A constructed at the rear wall of the shelf label display 2 is entered in fig. 5 by means of a dimension calibration 39. It is clearly visible here that the coil 12A is attached flat at the shelf label plane and is arranged there in correspondence with or even overlapping the spatial expansion of the wire loop L measured in the direction of the height of the shelf rail 2.

The pallet rail 3 furthermore has a fourth fastening structure for fastening the supply device 4 in order to push and fix the supply device 4 between the wall 29 of the pallet rail 3 and the cap rail 26 fastened by means of the third fastening structure at the end region (left or right end) of the pallet rail 3, so that the wire loop terminals C of the wire loops L available there are in contact with the supply device 4. For this purpose, the fourth fastening arrangement has a first insertion channel 40 which is configured below the first spacer element 37 at the rear side of the wall and opens into the bottom region 28, and a second insertion channel 41 which is configured above the first snap lip at the rear side of the wall and opens into the top region 27. The supply device 4, which may have its fastening rail 42, which is visible in fig. 6, is pushed into the two insertion channels 40 and 41. Furthermore, the fourth fastening arrangement has a circular hole 43 located at the top side end of the wall 29 and at the bottom side end of the wall 29, into which a fastening screw 44 (see for example fig. 6, but also see fig. 9 and 10) can be screwed from the side of the shelf rail 3 for screwing the supply device 4 with the shelf rail 3.

Fig. 6 shows a section through the pallet rail 3 according to the section B-B drawn in fig. 4, which section is oriented transversely (perpendicularly to the front side of the pallet rail 3) through the pallet rail 3 and extends from the right side of the section A-A at that point of the pallet rail 3 where the contact element 45 of the supply device 4 is configured. For improved clarity, a number of reference numerals not directly related to the fastening of the supply device 4 have been omitted in fig. 6.

Furthermore, two contact surfaces 46 are provided in this case, wherein each of the contact surfaces 46 is welded to one of the ring terminals C. In the case of a supply device 4 which is pushed completely into the carrier rail 3, i.e. when the supply device is positioned in the nominal position, the contact surface 46 is brought into contact with the contact element 45 which is in the form of a spring contact, so that a connection L is established with the wire loop and the wire loop can be used as a component of the second NFC interface 18. However, unlike this configuration, when the contact elements 45 are positioned closer to each other, the contact surface 46 may not be required, and the wire constituting the wire loop L may be directly contacted at the end region of the wire provided as the wire loop terminal C.

It should also be mentioned that at the other end of the pallet track 3, more precisely at the other end of the tube 34, the wire of the wire loop L extends in one piece from one tube 34 to the other tube 34.

Finally, reference should also be made to fig. 7 and 8, wherein fig. 7 shows the supply device 4 pulled out only slightly from the pallet track 3, and fig. 8 also shows the contact element 45 in a slightly modified illustration. Here, most of the reference numerals have not been required in order not to overburden the illustration.

In fig. 9, the long-term energy storage unit 13F (hereinafter referred to simply as unit 13F) is discussed in more detail in a further developed construction. As can already be seen from fig. 2, the unit 13F is fed by a power transfer unit 11B, which power transfer unit 11B generates a first supply voltage VCC1 on the output side when a (NFC) signal is present at the coil 12A. Depending on the quality of the NFC signal, the first supply voltage VCC1 may fluctuate.

On the input side, the unit 13F has a first voltage regulator stage (voltage regulator (voltage regulator)) 100 which supplies a regulated direct voltage with a defined value to a subsequent charging and current limiter stage (charger and current limiter (CHARGER AND current limiter)) 101. Stage 101 causes load limiting and causes the charging current to be limited so that the NFC signal is less strongly loaded and does not collapse. This may be important in order that other shelf labels mounted at the same shelf rail 3 can likewise be supplied and communication with them can also be performed. The stage furthermore causes the supercapacitor 13H to be charged correctly (according to its specifications).

The unit 13F furthermore has a cold start stage (cold start) 102, which is designed to operate the first electronic switching stage 103. The cold start stage 102 is responsible for the fact that the electronics downstream of the first switching stage 103 are supplied from the supercapacitor 13H only when the charge of the supercapacitor 13H has reached a minimum level, so that continuous operation of the downstream electronics is possible, and that the voltage of the supercapacitor 13H will drop so strongly that the downstream electronics will stop its operation again without loading with the downstream electronics. If the necessary minimum charge level is reached, the cold start stage 102 switches the second voltage regulator stage 104 by means of the first switching stage 103 onto the supercapacitor 13H, where, for example, a voltage of a maximum of 2.2 volts can be tapped. By means of the second voltage regulator stage 104, a higher (multiplied) supply voltage VCC2_1 of approximately 3 volts is generated, which is necessary for operating the central microcontroller unit 13 and is output to the central microcontroller unit 13. The central microcontroller unit then starts its operation. In this state, the microcontroller unit 13 can already exchange data D with the digital control unit 11J and thus also decode and if necessary also execute commands received via the first NFC interface 11 or receive or transmit data D.

Furthermore, the unit 13F has an energy threshold detection stage 105 which is designed to subdivide the energy stored in the supercapacitor 13H into three categories, for example, and to transmit this information to the microcontroller unit 13, for example, as an energy state ES (for example in the form of "good", "medium" or "bad").

Depending on the energy states ES present, the microcontroller unit 13 then determines which of the consumers 13A-13E can be supplied with its respective supply voltage VCC2_1 or VCC2_2, wherein it is also considered whether the respective consumer 13A-13E can be supplied (reasonably) at all, which can be derived, for example, from the received data D or commands. The microcontroller unit 13 thus decides which consumers 13A-13E can draw current from the supercapacitor 13H. Therefore, the supply voltage VCC2_1 is turned on for the display unit 13A only when the energy state "good" exists, for example. The image content of the screen 15 can then be changed and thereafter the power supply to the display unit 13A is stopped. So that the energy consumption from the supercapacitor 13H is kept as low as possible.

In order to achieve switching on and off of the individual supply voltages VCC2_1 or VCC2_2 of the individual consumers 13A-13E, the unit 13F has an output control stage (output control) 106, which is controlled by means of an output release control signal OE of the microcontroller unit 13. The output control stage converts the output release control signal OE into a switching signal for the two other switching stages 107 and 108.

By means of the second switching stage 107, for example, that supply voltage VCC2_1 which is provided for the microcontroller unit 13 can thus also be supplied to the consumers 13A to 13B, while for the consumers 13C to 13E the supply voltage VCC2_2 which has a different value (for example 5 volts) from the supply voltage VCC2_1 can be switched on by means of the third switching stage 109, which value is generated by means of the third voltage regulator stage 109.

Of course, this action can also be applied individually for each consumer 13A-13E if a corresponding number of switching stages and, if necessary, also voltage regulators are provided according to the number of consumers.

Finally, it is pointed out again that the figures described in detail above are merely examples, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. For the sake of completeness, it is also pointed out that the use of the indefinite article "a" or "an" does not exclude that the relevant feature may also be present a plurality of times.

Claims (11)

1. A method for operating an electronic shelf label system (1), - wherein the system (1) has shelf tags (201-211), which are fastened to the shelf rails (3), wherein the shelf tags (201-211) are configured to be supplied with energy in a contactless manner, and The shelf rail (3) has a supply device (401-403) for supplying energy to the shelf tags (201-211) fastened to the shelf rail in a contactless manner, and The shelf rail (3) has at least one wire loop (L), wherein the wire loop (L) is a component of a supply device (401-403) of the shelf rail (3), and the wire loop (L) is used to output a signal that can be generated by the supply device (401-403) for the purpose of supplying energy to a shelf tag (201-211) positioned at the shelf rail (3) corresponding to the wire loop (L), - wherein according to the method, the signal is generated by means of the supply device (401-403) and output via the wire loop (L), and the corresponding shelf tag (201-211) positioned corresponding to the wire loop (L) stores the electrical energy transmitted from the supply device (401-403) to the shelf tag (201-211) by means of the signal in a rechargeable long-term energy storage device (13H), and uses the electrical energy for operating the shelf tag outside the time interval when the signal is present, - wherein at least one shelf tag (201-211) of the system (1) has at least one electrical consumer (13A-13E) which causes electrical power consumption outside of the time intervals in which the signal is present, - wherein according to the method, each shelf tag (201-211) having such an electrical consumer compensates the power consumption of the electrical consumer outside the time interval in which the signal is present by means of the electrical energy stored in the long-term energy storage device (13H), The corresponding electrical consumer (13A-13E) generates data (D) during the activity of the electrical consumer that causes the electrical power consumption outside the time interval when the signal is present, stores the data (D) and subsequently, i.e., transmits the data (D) from the shelf label (201-211) to the supply device (401-403) during communication with the supply device (401-403) within the time interval when the signal is present. 2. The method according to claim 1, wherein the supply device (401-403) establishes a communication with one or more selected shelf labels (201-211) by means of the signal in addition to the energy supply, and When the signal is present, each shelf tag (201-211) checks, by evaluating the signal, whether the shelf tag is selected for communication with the supply device (401-403). 3. The method according to claim 2, wherein each shelf tag (201-211) first sets up a power supply to the shelf tag by means of the signal when the signal occurs, and then checks whether the shelf tag is selected for communication with the supply device (401-403). 4. A method according to any one of claims 2 to 3, wherein each shelf tag (201-211) which determines that it has not been selected for communication with the supply device (401-403) reduces its activity to: using the signal for storing electrical energy during the entire remaining time interval in which the signal is present, until the long-term energy storage (13H) is as fully charged as possible. 5. The method according to claim 1 , wherein the respective electrical consumer (13A-13E) processes data (D) during the activity of the electrical consumer causing the consumption of electrical power outside the time interval in which the signal is present, said data having previously been transmitted from the supply device (401-403) to the shelf tag (201-211) having the electrical consumer (13A-13E) during the communication between the supply device (401-403) and the shelf tag (201-211) and stored therein. 6. An electronic shelf label system (1), the electronic shelf label system - having a shelf rail (3) and a shelf tag (201-211) fastened to the shelf rail, wherein the shelf tag (201-211) is configured to be supplied with energy in a contactless manner, and wherein each shelf rail (3) has a supply device (401-403) for supplying energy to the shelf tag (201-211) fastened to the shelf rail in a contactless manner, and each of the shelf rails (3) has at least one wire loop (L), wherein the wire loop (L) is a component of the supply device (401-403) of the shelf rail (3), and the wire loop (L) is used to output a signal that can be generated by the supply device (401-403) for the purpose of supplying energy to the shelf tag (201-211) located on the shelf rail (3) corresponding to the wire loop (L), wherein the shelf tags (201-211) have a rechargeable long-term energy storage device (13H), and wherein the shelf tag (201-211) is configured to store in the long-term energy storage (13H) energy transmitted to the shelf tag from the supply device (401-403) by means of the signal, and to use the energy stored in the long-term energy storage (13H) for operating the shelf tag outside the time interval when the signal is present, wherein at least one shelf tag (201-211) of the system (1) has at least one electrical consumer (13A-13E) which causes electrical power consumption outside the time intervals in which the signal is present, and wherein the shelf tag (201-211) having such an electrical consumer compensates the power consumption of the electrical consumer (201-211) outside the time intervals in which the signal is present by means of the electrical energy stored in the long-term energy storage (13H), The electrical consumer (13A-13E) is designed to generate data (D) outside the time interval when the signal is present and to store the data (D), and the shelf label (201-211) has an electronic device which is designed to make the data (D) stored by the electrical consumer (13A-13E) available to the electronic device during the time interval when the signal is present and to be able to be transmitted to the supply device (401-403) during communication with the supply device (401-403). 7. The system (1) according to claim 6, wherein the supply device (401-403) is designed to establish a communication with one or more shelf tags (201-211) for the purpose of energy supply by means of the signal in addition to outputting the signal, and Each shelf tag (201-211) is designed to check the signal when it is present to determine whether the corresponding shelf tag (201-211) is selected for communication with the supply device (401-403). 8. The system (1) of claim 7, wherein each shelf tag (201-211) is configured to, upon recognizing that the shelf tag has not been selected for communication with the supply device (401-403), reduce the activity of the electronic device of the shelf tag to use the signal for storing electrical energy during the entire remaining time interval in which the signal is present until the long-term energy storage (13H) is as fully charged as possible. 9. The system (1) according to claim 6 , wherein the shelf tag (201-211) has an electronic device which is designed to make available to the electrical consumer (13A-13E) stored data (D), which data has been communicated from the supply device (401-403) to the shelf tag (201-211) with the electrical consumer (13A-13E) during communication with the supply device (401-403), and wherein the electrical consumer (13A-13E) is designed to process the data (D) outside of the time interval in which the signal is present. 10. The system (1) according to any one of claims 6 to 8, wherein each shelf tag (201-211) has a first NFC interface (11), and wherein each supply device (401-403) has a second NFC interface (18) for supplying energy to the shelf tag (201-211) and for communication between the supply device (401-403) and the shelf tag (201-211), and the wire loop (L) is a component of the second NFC interface (18). 11. A system (1) according to any one of claims 6 to 8, wherein the supply device (401-403) is designed to be supplied with energy in a contactless manner, and the energy transmitted to the supply device in a contactless manner is stored in a rechargeable supply energy storage device (25), and the energy stored therein is used for the operation of the supply device itself and for supplying energy to the shelf tags (201-211) in a contactless manner.